TORONTO -- Much is made about Guillermo del Toro's Pacific Rim being an industry game-changer because the $190 million sci-fi blockbuster nabbed 75 percent of its box office from overseas, and a large portion of its foreign cume from China.

But John Knoll, chief creative officer at Industrial Light & Magic, points to another way in which the monsters vs. machines spectacle movie was a rule-breaker: a prior agreement between the VFX guru and del Toro to limit waste by keeping the extensive effects work efficient and cost-effective in postproduction.

"What I tried to do on the picture, in order for us to take this very ambitious picture, with a large number of shots, and a high degree of complexity, and with a limited budget, the pitch I made to Guillermo was, 'We can do this by making this the most efficient show we've ever done,' " Knoll tells The Hollywood Reporter.

Knoll, who is set to give a keynote speech at the Spark FW 2014 conference in Vancouver on Saturday, said waste was minimized by limiting changes during postproduction when it came to completing complex character animation, lighting, digital environments and advanced fluid simulation work.

That frugality is rare in Hollywood, where a virtual environment offers directors endless flexibility in postproduction.

"A lot of filmmakers understand that the work is done digitally, and it's technically possible to change it late in the game. And so they do, because it's something you can do, and they're used to being able to do it," Knoll says. "It is very wasteful."

The irony is that directors limit changes in live-action moviemaking -- where a set will be built once, for example, not four times -- owing to the sheer expense.

"So what Guillermo did, which is relatively unique in this business, is make a commitment to the (VFX) work and treat it more like it's live action," Knoll says.

For del Toro, the master of the creature feature, a willingness to limit VFX costs is made easier by his traditional reliance on physical effects, whether through makeup or life-size models.

"The visual effects need to be the last resort," del Toro said Wednesday from Pinewood Toronto Studios, where he is currently directing The Strain TV series for FX and is soon set to begin shooting Crimson Peak for Legendary Pictures. "Sometimes it's the last resort that you know you will try right away, like in Pacific Rim, where it's impossible to build a robot that is 25 storys high, or create a monster in a suit, which was not the effect I wanted."